Host Oxidative Response Capacity Determines Longevity Outcomes of Microbial Interventions

Area of Science:

• Microbiology
• Genetics
• Aging Research
• Host-Microbe Interactions

Background:

• Microbial communities are crucial for host aging, but the role of natural genetic variation in microbiota-driven longevity is not well understood.
• Understanding these interactions is key to developing strategies for healthy aging.

Purpose of the Study:

• To investigate how genetic diversity in host organisms influences their response to microbial communities in the context of aging.
• To identify specific host genetic factors that mediate lifespan regulation by the microbiome.

Main Methods:

• Screening of bacterial isolates across genetically diverse Caenorhabditis elegans strains.
• Utilizing classical genetic analysis, quantitative trait locus (QTL) mapping, and CRISPR-Cas9 gene editing.
• Assessing lifespan, tissue integrity, and redox buffering capacity.

Main Results:

• Identified significant phenotypic heterogeneity in lifespan responses to bacterial isolates among different C. elegans strains.
• Discovered that skn-1 (Nrf2) and gsy-1 (glycogen synthase) are critical host determinants of microbiota-driven aging.
• Demonstrated that compromised redox homeostasis in susceptible strains leads to oxidative stress and premature aging upon microbial challenge.
• Showed that antioxidant supplementation rescues lifespan defects in susceptible individuals.

Conclusions:

• Redox homeostasis is a central mechanism in host-microbe-aging interactions.
• Host genetic background dictates whether microbial signals promote longevity or accelerated aging.
• Findings provide a framework for precision microbiome interventions based on host genetics.